The present invention relates to an elongate retaining element for building sheets having as seen in cross section perpendicular to its direction of elongation, a head part for engaging at least one building sheet. The invention further relates to an assembly such a elongate retaining element engaging at least one building sheet member.
Such an elongate retaining element is known from GB-2167101-A, which discloses a retaining element having a head part and a base part connected by a connecting flange. The head part engages with the free end of at least one building sheet, which is at least partially curved over the head part of the retaining element. The head part is substantially triangular in cross section and has rounded vertices that engage with the building sheet.
A disadvantage of such prior art retaining elements is that movement of the building sheets over the retaining element, caused by e.g. thermal expansion or wind suction, generates unpleasant noise.
One proposed solution to the problem of noise is proposed in GB-342933-A in which the head part of the retaining element is provided with a solid coating comprising an organic powder coating.
Another proposed solution is known from DE-4217221-A1 disclosing a holding element for use in roof constructions. The holding element is formed by a folded sheet with a curved end-section forming a head part. The head part co-operates via ball bearings or tapered wheels with a separate member extending across the direction of elongation of the holding element. The building sheet member is flanged over this separate member.
An object of the present invention is to provide an improved retaining element. A further preferred object of the present invention is to provide a retaining element that reduces the noise generated when building sheets when sliding in use over the head part of the retaining element.
One or both of these objects are obtained by a retaining element having in plane or as seen in cross section perpendicular to its direction of elongation, a head part which is substantially triangular in cross section, said head part comprising one or more movable rotationally symmetrical elements, said elements being positioned at one or more vertices of the triangle, and characterised in that said head part comprises one or more mountings in which the elements for engaging in use the building sheet are mounted and in that the mountings are attached to the head part by fixing means.
The movable elements allow the engageable building sheet to slide over the head part. The presence of movable elements in the head part significantly reduces the friction between the head part and the engageable building sheet enabling the building sheet to slide easily over the head part of the retaining element without generating significant noise. Wearing of the building sheet and the head part of the retaining element and resultant dust formation is also reduced. A further advantage is that reduced friction between the head part and the building sheet reduces the mechanical load on the joint with a support structure. A high mechanical load on the retaining element is particularly undesirable where the support structure to which a retaining element is attached is less robust such as for example, insulating glass wool or foam glass. By reducing the mechanical loading to which the retaining element is subjected the present invention reduces the risk of the retaining element failing. The movable elements are rotatable to facilitate the sliding of a building sheet over the head part. The movable elements are preferably rotationally symmetrical and can freely and smoothly rotate reducing the chance of noise generation as a building sheet slides over the head part of the retaining element. The head part comprises one or more mountings in which one or more movable elements are mounted. The mountings preferably extend in the direction of elongation of the retaining element. Of course the head part may comprise more than one mounting and each mounting may contain multiple movable elements. The mountings facilitate assembly of a retaining element, as the movable elements do not have to be individually mounted to the retaining element.
The head part of the retaining element is substantially triangular in cross section and has a movable element positioned at one or more vertices of the triangle. The movable elements are therefore positioned on the head part at the points where a building sheet contacts the head part and are thus optimally positioned to reduce the friction between the head part and a building sheet sliding over the head part.
In an embodiment the movable elements are preferably spherical and can thus rotate in all orientations further reducing the chance of noise generation. The spherical movable elements preferably have a diameter in a range of 1 mm to 10 mm to ensure that they can be easily mounted on the head part and effectively facilitate in use the sliding of a building sheet over the head part of the retaining element.
In an embodiment the movable elements are preferably made from metal, plastic or ceramic or a combination of these. Metal and ceramic are both hard and resistant to wearing offering good durability whilst plastic such as PTFE (polytetrafluoroethylene) is easily formable and resistant to temperature variations. The metal used is more preferably sinter metal e.g. sinter bronze for increased hardness and wear resistance.
In an embodiment the retaining element preferably comprises a base part and a connecting flange connecting the base part and the head part wherein the head part, excluding the mountings and movable elements, the base part and connecting flange are made from metal which can be extrusion formed or a combination of metal and plastic which provides an insulating barrier between the interior of a roofing or cladding assembly and the building sheets for example as known from EP-1236840-A1 (incorporated herein by reference). The head part, excluding the mountings and movable elements, the base part and connecting flange are preferably formed from extruded aluminium.
The retaining element known from international application WO-98/53158 (incorporated herein by reference) may be provided with a head part as proposed in the present invention.
A further aspect of the invention relates to an assembly for roofing a building or cladding e.g. the façade of a building comprising one or more elongate retaining elements as described above whereby the free end of at least one building sheet is flanged over the head part of the elongate retaining element engaging one or more of the movable rotationally symmetrical elements, and having the advantages as set out above.
A further aspect of the invention relates to a mounting, in which movable elements are mountable, for use in the elongate retaining element according to the present invention.
The present invention is described further by way of example with reference to the accompanying schematic drawings in which:
The retaining elements can of course also be mounted horizontally for example as part of a wall cladding or façade assembly for a building, or at other angles from the vertical.
Having now fully described the invention, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made without departing from the spirit or scope of the invention as hereon described.
Number | Date | Country | Kind |
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03078078.7 | Oct 2003 | EP | regional |
04076371.6 | May 2004 | EP | regional |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP04/10769 | 9/23/2004 | WO | 4/22/2005 |